She went up to the 9th floor first.
When the others heard the alarm and were still panicking about what had happened, she quickly walked into the female washroom and entered a cubicle. She gritted her teeth and pulled out the 20-centimeter-long steel needle on her right arm.
Blood spewed out and wet her sleeve. Face pale, Qiao Nian tore off the T-shirt's inside fabric and tied it under the wound to temporarily stop the blood.
She threw the steel needle on the ground and silently left the washroom. Then, she hurriedly pressed down on her baseball cap, turned into the stairwell again, and went to the 11th floor.
Turning the corner and seeing a lone female employee, she rushed over to cover the other party's mouth, knocked her out, and dragged her into the washroom.